The car in question is my daily driver, 97 z28 M6 30th anniversary

sorry for the long post, want to give as many details as I can!

OK so those of you who may have seen my past "cooling issues" threads will know what I've been dealing with.. I've spent wayyy too much time messing around with this, thinking I had a bad headgasket, ect... Basically my car is full bolt ons, with no tune yet. I'm waiting to put my headers & exhaust on, then I'm getting a tune for everything and lowering the fan temps.

Anyway, every since I got the car it runs hot. Everything is new or has been replaced - waterpump, radiator, 160* t-stat, the works. When the car is cruising fast and air is rushing in, it stays nice and cool, either at 1/2 or below on the temp gauge. But when city driving and sitting still it get's way up there, about 3/4 up nearly overheating before the fans finally kick on, and even then it stays real hot. Scaulding your hand if you pop the hood HOT. The system has been flushed completely, everything's new, bled a million times, all good in that department.

I was underneath the car yesterday and I haven't noticed it before but there was finally something to go off of, a small weep from the waterpump hole. It's a small drop every few seconds, but I think this what's been causing everything, I just haven't had a sign before now to figure it out. So does this mean the waterpump is bad 100%, or the seals are bad? Either way I know the pump needs to be replaced, just trying to figure out if THIS is indeed what is causing my cooling issues.

When I drive the car for a while then park it, I hear a loud bubbling of pressure trapped all inside the cooling system, and when I try and open the bleeder/s the coolant overflows out of the check resevoir. I have pressure tested the system a few days ago, pumped it up to 18psi and even went a little over, and there were absolutely no leaks, it held pressure for a good 10 minutes before I pulled the tester off.

My 383 car (which I don't drive anymore) has a Meziere HD waterpump installed, brand new pretty much never used. I'm thinking of putting it in this car to beef up the efficiency, my 383 car runs so cool you can beat the **** out of it for 2 hours pop the hood and everything is cool to the touch. Should I put the EWP in the 97, and will it fit? I've done a SLP lid conversion on the 97 so the radiator is tipped back a bit, would it still fit?

 

By the way the car runs 100% ***** to the wall strong - no coolant or oil loss or mixing whatsoever, no smoke, no smells, nothing out the exhaust, it's absolutely perfect and runs like brand new aside from getting hot like this.

 

as for the pump being bad, its gotta be. The weep hole is there for one reason and one reason only, to show when the water pump is crapping out on you. IMO, you should swap in the ewp! that sucks that a brand new pump is doing that though!

 

Tell me about it dude! The previous owner replaced the pump so there's no telling how many miles or what kind it is, but I can tell it's new from the fresh cast housing so it can't be too old.

Even IF my WP wasn't bad since I drive this car a lot and we've been having 100+ degree days the entire summer here in WI I've been wanting to swap in that Meziere HD, that thing kicks ***.

I had to clearance the fan shroud on my 93 383 to fit the Meziere, but that was with the LT1 K&N intake setup with the stock radiator shroud in the stock position. with my SLP lid conversion, the radiator lays back a bit on the 97 so I'm wondering if the pump will work with this setup? If anyone has experience with this please let me know, I mean i guess worst case scenario I can pull the fans from the shroud, move them out of the way, and fix them to the radiator using spacers to get them out of the way of the Mezeire. But if I don't have to do that, let me know!

 

The electric pumps move LESS water at medium to high rpm, the improve idle cooling but waterflow at idle is not an issue.

Sounds to me like you either have a dead fan or do not understand just how high the fan temps are. In stock form with a 180 stat the engine will run about 195 on the highway BUT the primary fan temp is over 220 and on the b-body at least the secondary is 242. With a 160 stat on the highway you will run about 175 which allows the fan temps to be brought way down to say 195 and 205.

Basicall what I am saying is first verify both fans work, then if you still think it is overheating get it reprogrammed, Is your pressure cap good?
The weeping waterpump will NOT cause overheating till it weeps a LONG time and you are low on coolant, certainly time to change it but to put a lower flowing electric on to "improve cooling" when flow is not the issue anyway would be just plain stupid.

 

as said your current 'weep" is not the cause of overheating but is a solid sign you need to replace wp

the EWP, not going to debate about its cooling abilities over the mechanical type, but FWIW I have had one for 13 years with no issues in any driving condition includeing 115 degree outside desert temps. A EWP will elinimate the typical OEM WP leaking and pissing on opti issue.

you are running a 160 stat with a stock tune. not a good thing as you most likely are running rich now. get a tune, your headers will not influence that.

pull the connector on the front of the WP and both fans should come on..if not you have a fan problem so fix.

I suspect once you get a tune with lower fan on temps your cooling issues will go away...and your car will run better.

 

replace waterpump and get a manual fan switch. thats what i did. it has helped me alot.

 

The only reason to consider a manual switch is for a car with an electric pump that you want to cool down at the track between passes.

The right way to do it is to have the pcm reprogrammed for lower fan on temps, you are not introducing any new connections or failure points this way plus you get the added benefits of fueling and spark changes, tranny tweaks on an A4 cars. Plus with the pcm in control there is nothing for you to remember you just get in the car and drive.

 

If you're hearing bubbling and what not when you shut it off, there's air in the coolant system......that very well could be your whole problem (fix the WP anyway). I would just replace the WP, properly bleed the coolant system to get out all air then see how it runs....if it's still getting hot, get the fans tuned and see what happens.

 

Not necessarily. It could actually be the coolant boiling. The system is supposed to be pressurized to raise the boiling point of the coolant.

1)A few things to check. Make sure that the gauge is actually reading right. Your dash gauge may be off.

2) check the cap on the radiator it may not be keeping the system at the proper pressure.

3) make sure you aren't running strait antifreeze. Antifreeze is not actually a coolant it is just to keep the system from freezing and lubricate the pump. You need to run at least a 50/50 of antifreeze and water. The water actually does the cooling. depending on your area you may want to 60/40 or what ever is recommended for your region.

 

I have an slp fan switch setup. It allows me to put the fans on low or high or auto. the computer can still send the signal to kick the fans on high when its on low. I think its a great addition to the car. I do agree though proper programing is a good idea. I like having it for heavy traffic on really hot days I don't like nor see a reason to let the coolant temps spike.

 

If that's the case then you still have to get the air out from the boiling coolant or the issue will just get worse....and figure out why it's getting so hot in the first place....(WP, fans, air bubbles in system, thermostat) Plastic bag on your radiator? LMAO...it happens.

 

If reprogrammed the temps wont spike.
Maybe I am just getting old but if I am sitting in traffic on a hot day the AC is on so the fans run for that.

I don't see the point in spending money to turn the fans on manually. The $70 Thunder asks for the kit can go a long ways towards reprogramming.

 

93z383 is a liar. I bought a cutout from him over a month ago and he still hasn't shipped it and won't message me back.

 

I can't stand a thief GTFO 93z383

Karma's a bitch, now he's got cooling issues to deal with and a public shaming on here

 

Thanks man. I'm giving him hell trying to get the word out. I don't want anyone else getting screwed over

 

I dont have AC on my car so its a fan switch or I let them go up. Ion did reprogram my computer. I like if I get in heavy traffic on a hot day I just flip the switch from auto to low. it keeps the temps below 200 that way. I dont know I just like it I do think you are right though its not needed but it just makes me feel more comfortable. I could blow 60 bucks on far worse stuff.

 

Look up on how to clean your ac condenser in the car, people dont realize how much keeping it clear matters to airflow going to the radiator

 

The electric pumps move LESS water at medium to high rpm, the improve idle cooling but waterflow at idle is not an issue.

 

96s and 97s do run hot in city driving, my old 96 would get close to the red zone idling or in heavy traffic. get a tune so the fans come on sooner.